Fluad®-MF59®-Adjuvanted Influenza Vaccine in Older Adults

Abstract

Influenza directly or indirectly contributes to the four leading causes of global mortality, at rates that are highest in older adults. As the proportion of older adults in the Korean population is greater than in most other countries, influenza prevention is a greater public health priority in Korea than elsewhere. Conventional inactivated influenza vaccine (IIV) is less immunogenic and efficacious (-50%) in older than in young adults, but adjuvanting the vaccine with oil-in-water emulsion MF59® increases immunogenicity, resulting in comparatively higher levels of hemagglutination inhibition antibodies and greater protection against all influenza, as well as cases requiring hospitalization. A recent observational study demonstrated that the adjuvanted vaccine protected older adults against influenza in a year when nonadjuvanted IIV was ineffective. In another multiyear study, the adjuvanted vaccine was estimated to be 25% more effective in preventing pneumonia and influenza hospitalizations compared to nonadjuvanted vaccine. Although MF59-adjuvanted vaccine is transiently more reactogenic than nonadjuvanted vaccine, there is no evidence that it increases risks for serious adverse events, including those with an autoimmune etiology. Experience thus far indicates a favorable balance of benefit to risk for MF59. This may reflect the adjuvant's mechanism of action in which the squalene oil emulsion increases antibody responses to co-administered antigen without acting more generally as an immunopotentiator.

Heterogeneous estimates of influenza virus types A and B in the elderly: Results of a meta‐regression analysis

“…Indeed, that study did not quantify the natural attack rate of IVA/IVB in the elderly, as two of the only three studies identified did not report data of interest, while the third reported a natural attack rate of zero. The paucity of studies identified is not surprising; indeed, randomized placebo‐controlled trials have been very uncommon (at least in recent years) in this population group for purely ethical reasons, in that annual influenza vaccination is recommended for the elderly . This is why epidemiological and surveillance evidence is of importance …”

The avian influenza vaccine Emerflu. Why did it fail?

“…Until recently, the use of adjuvants in influenza vaccines has been limited, with only the MF59-adjuvanted trivalent seasonal vaccine licensed, and alum not widely investigated [35]. This is despite the use of aluminum salt adjuvants in vaccines since the 1920s, their status as the only licensed adjuvants in the USA until 2005, and the reduced effectiveness of unadjuvanted seasonal influenza vaccines in vulnerable populations such as the elderly [36,37].…”

A clinically applicable adjuvant for an atherosclerosis vaccine in mice

“…CpG ODN was recently approved as a hepatitis B virus vaccine adjuvant. Addavax is a squalene‐based adjuvant similar to MF59, which is FDA‐approved and licensed in Europe for a seasonal influenza vaccine for elderly people . Here, we report that vaccinating Apoe ‐deficient ( Apoe −/− ) mice with ApoB P6 in Addavax was as atheroprotective as P6 in CFA/IFA.…”